Soaking-pit furnace



Fpw. MANKERv SOAKNG- PIT FURNACE Filed Nov. 1927 2 sheets-sheet R E w K A N m 4 IIIIIL, W .l J 7. w r WM 1 N2, a f i ,Q m 1Mo I. a m L fw 1 L 1| \0- l I i Patented Apr. 30, 1929.

UNITED STATES .PATENT oFFl'cE.

EORREST W. MANKER, OF TOLEDO, OHIO, .ASSIGNOR TO THE SURFACE COMBUSTION COMPANY, INC., OF TOLEDO, OHIO, A CORPORATION' OF NEW YORK.`

soAxiNe-Prr FUBNACE.

Application filet"` November 17, 1927. Serial No. 233,851.

This invention relates to soaking pit furnaces and has among its objects to provide a soaking pit furnace of such construction .that the hot gases generated in one ormorepits by burning gaseous fuel therein may be passed through other pits of the series to preliminarily heat the ingots contained therein; to provide a firing arrangement for the individual pits such that uniform heating of the entire ingot may be had in the minimum amount oftime; and to provide other improvements in soaking pit furnaces as willv more fully appear hereinafter.

Referring to the drawings wherein the preferred constructional form of the' furnace is shown,

Fig. l represents the furnace in plan with various parts associated therewith more or less diagrammatically indicated in dotted lines. v

n Fig. 2' represents aside elevation of the furnace, some of the interior construction being indicated in dottedlines.

Fig. 8 is a vertical sectional view of the.

furnace on lineB-S of Fig. 4.

Fig. 4 is a horizontal cross section of the furnace on lines A-B-C-D-E-F--Gr and A-B-C-D-E-H respectively of Fig. 3, the upper half of Fig. 3 being taken on the last named lines.

Fig. 5 is a vertical section taken on the lines J-K-L and lVl-K--L respectively of Fig. 3, the loft hand side of the view beingI takenl on the first. named lines.

For tliepliipose of illustrating the nature of the invention a soaking .pit furnace having four pits has been shown-but as will become more evident as the .description proceeds a greater or' lesser number of pits may be employed without departing from the 4spirit of the invention. The pits are generally indicated by letter P, the prime numbers being employed to simplify the description.

Referring now more particularly to Figs. 3, 4 and 5, it will be seen that the pits are separated from each other by dividing walls 10 through each of which extends a passage 3Q. the purpose of which will more fully appear hereinafter and-each pit is .provided with the conventional cover l1. (See Fig. l.)

Each pit is provided witliits own firing towards its opening on the pit. Combustible gases are delivered to the combustion chamber by a plurality of burners 16 connected with a suitable source of supply of gas. These burners have been shown as of the air-gas mixing type, the primary air entering the individual burners through a suitable shutter at the back of the burners, one element of the means for regulating the shutters being indicated at 18. Opening on the pit below the combustion chamber 14 and adjacent th pit hearth 12 is a flue or exhaust passage 20 through which the products of combustion may flow out of the pit. This passage continues downwardly as` indicated at 22 and then laterally as at 24 and opens on a flue 26 between which and said lateral passage is positioned a damper 28. Said iue E26 is common to all of the pits and exhausts the products of combustion A received -from the pits into a stackv not shown,'the outlet from the 'fine being indicatedat 30 (Fig. 4).

Opening'on the side Wall of the pit opposite to that on which the combustion chamber 14 opens is another combustion'chamber 14 sniilar in 'all respect to the iirst described combustion chamber. The other appurtcminces such as burners, the exhaust.

passage. the damper and lue are also dupli-.

cated in connection with the combustion 4 chamber l14 as has been indicated by primchambers meet eachother at the center of the pit and inter-mingle and circulate more f completely around the ingots in the pits than is possible of attainment where but a single combustion chamber opening on a side wall of the pit is employed. More uniform heating of the ingots is therefore obtained. -Furthermore by"withdrawing the products of combustion from the pit through oppositely positioned exhaust passages 20, 20 arranged l adjacent the hearthof'the pit it will be readily appreciated that the lower part of the pit will be just as completely heated by the circulatingl gases as the upper part'of the pit with consequent'uniformgheating of the entire length'of the ingotstherein.

As previously stated each combustion chamber is constructed to increase in crosssectional area from its closed end outwardly towards 'the pit. By .providing an expand- 4ving combustion chamberA the burning gases expand within the combustion chamber and l flow into the pit under relatively low velocity with the result tliat localized or spot heating lof the iiigots is .eii'cctually prevented.

It `Will now be appreciated tliat,yfrom one point in View, the pits are independent units susceptible of individual control and yet they are so coordinated that they may be operated in combination to obtain certain desirablel results. By opening 'all' of the dampers 28? (28'), all of the pits exhaust into the com mon collecting flue 26 (26') and very little if -any combustion gases pass from one pit to thek next adjacent pit through connecting passage 32. Suppose it is desired to turn all of the combustion gases through pit P3; All of the dampers 28 (28') are then closed except those 'controlling the exhaust from P3.'y 'P1 then vents into P2, the latter into P3 and P4V into P3. It may also be noted that by ypartially opening the dampers 28, (28') some of the' combustion gases from'the pit controlled by such dampers may discharge its combustion gases partly into the adjacent pit or pits and partly into the'common collecting fluid 26 (26'), thus' enabling `great flexibility of control to behad As already indicated each pit is provided with firing means at its opposite side walls both of which means are adapted for siinul1 taneous operation. vIn Fig. 1I have shownv how I prefer tocontrol the individual tiring units andalso a controlling system for tlie various dampers. Inasmucli as the controlling means are the same for each pit the description will be confined to the controlling means associated with pit P4.' Each group of burners 16and 16' has its own manifold 34 and 34', respectively. Leading from each manifold is a gas pipe36 .and 36'respectively, the'` pipes Connecting With- 'a common pipe 38 provided with a valve 40, the pipes 36 andv 36. each also having a valve 42 and 42 tively. For regulating the admission of air Ito the burners each burner has its individual shutter, an operating element of which is inldicated at 18 (18'). In order to operate said shutters simultaneously there is provided a 4shaft-44 (44'.) on which aremounted suitable means for operating the shutter-operating means 18 (18'). Leadingfrom the two shafts 44 and 44 are cables`"46 and 46', respectively, which lead to a motor 48 adapted to lie-controlled by aswitch or other powerrespecmirava controlling means`50. It will now be readily appreciated that'joint control of both sets of burners is had both to the gas and air supply and that 'as regards the gas. supply the' valves 42and 42' permitindividual control of each set of burners. Individual as wellfas joint control ofthe burners obviously give desirable exibility in the firing system.

lJoint control isalso had on thetwo dampers 'associated witheacli pit. As shown athere is provided a motor 52 (52') for each damper,

this motor lbeing set into operation by a suitable controlling means 54the motor being operatively connected to its damper in any suitable manner .as by a cable 56 (56') vIt will now be seenl that the Ipresent invention provides a soaking-pit furnace Which in addition to other desirable' features of construction allows recoveryof waste heat from y 2. In a furnace having soaking pits arranged side by side, the combination of a passage between'adjacent pitsthroug'h which combustion products may pass from one pit to another, means' individual to each -pit adapted to fire thereinto simultaneously from 4opposite directions, exhaust passages leading from the respective pits adjacent the bottom thereof, and dampers in said passages" foi' regulating the volume of combustion products which may be passed fromone pit to another.

yed in connectionwithsoaki 3. In a furnace having soaking 'pits' ari ranged side by side, the combination of a passage between adjacent pits through which'l products of combustion may pass fromy one I pit to another, exhaust of the individual pits from opposite sides thereof, means -for introducinghot gases'into the pits, andv dampers in said exhaust passpassages leadingioutages for indirectly controlling the volume of combustion products which may pass from one ing passage therebetween.

'.4. A method of firing a series of soaking pits which are adapted to be fired by introducing combustible gases thereinto compriswhole number of pits, passing the resultant hot combustion charged by way of the pits intervening between said last charged pit and the pit most products towards the lpit last pit to another through the communicat- -ing introducing such gases into less 'than the remote therefrom and exhausting `such com- Whole number of Said pits and venting the bustion products from the said last charged combustion products from the directly fired pit` pits through the last charged pit by IOW 10 5. Ainethocl of firing a Series of Soaking paths which include intermediate pits. 5 pits which are adapted to be fired by intro- In testimony whereof I affix my signature.

ducing combustible gases thereinto compris- 'l ing introducing such gases into less than che i FORREST W. MANKER. 

